This invention relates to EMD locomotive engine protection devices and more particularly to preventing conditions causing the trip of the device in an EMD locomotive engine during a computer controlled automatic engine restart.
Railway locomotives are off service for substantial periods of time and are generally shut down when they are not going to be in use for extended time periods. Since some locomotive systems may be harmed if the engine is shut down for too long, there are automated systems designed to stop and restart an engine automatically in the absence of personnel. Whether an engine is being started automatically or manually there are engine protective devices designed to sense certain conditions in an engine's systems during start up and running which will shut an engine down under certain conditions. Unfortunately, and especially after an EMD locomotive engine has been shut down for a long period of time, transient conditions on start-up may be sensed by such protective devices and result in the engine being immediately shut down again. This condition defeats the advantage of an automatic engine start/stop system (AESS) and may require the need for personnel to be available to restart such an engine by overriding the protective devices.
One protective device for engines manufactured by the Electro-Motive Division of General Motors (EMD) is a differential water and crankcase pressure detector system. This device monitors for abnormalities in the engine cooling system and crankcase pressure. If potentially harmful abnormalities are sensed the engine is shut down. Sometimes sensed abnormalities at engine start-up due to transient conditions, such as low coolant system pressure, cause this protective device to produce an unnecessary engine shutdown. In these EMD protective devices of Electro-Motive Division of General Motors locomotive engines there are manual resets which require the presence of qualified personnel to restart the engine, thus often defeating the advantage of an AESS system on such engines.